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Per
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Ok.
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garage chemist
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Ethyl chloride is apparently still available in pharmacies as a local anesthetic ("ice spray", though all of the metal icespray-cans contain something
different today). You have to ask specifically for Chloräthyl.
Also enter Chloräthyl into google- you will find common prices for 100ml of it in pharmacies (around 5€).
This would also be a good idea for nitroethane preparation.
You just have to react it with silver nitrite.
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Per
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Why doe´s the preparation of nitroethan work with silver nitrate and why doesn´t work it with sodium nitrate?
I can´t imagine that.
Looking for Chloräthyl seems to be a good idea, thank you.
last time I tried to prepare ethyl chloride by adding a 25%HCl solution to a mix of ethyl alcohol and konz. H2SO4.
I heated it a little bit and it envolved white gases, I tried to condense them but it does not work, not even with a ice-alcohol mix.
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Nicodem
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| Quote: | Originally posted by Per
Why doe´s the preparation of nitroethan work with silver nitrate and why doesn´t work it with sodium nitrate?
I can´t imagine that. |
I don't know where you heard that nitroethane can be made with silver nitrate, but you can be sure you got it wrong. Silver nitrate and ethyl chloride
in DMF or other dipolar solvents would give you ethyl nitrate and not nitroethane. With sodium nitrate you would get no reasonable reaction due to the
already mentioned too low difference in the chloride/nitrate nucleophilicity (this problem is overcome in the case of silver salts by the formation of
the highly insoluble silver halides – this drives the reaction forward). As already mentioned by Garage chemist, for the preparation of nitroethane
from ethyl chloride you would need silver nitrite (AgNO2, also know as silver nitrate(III) as opposed to the nitrates which are salts from the
nitrate(V) ion that is NO3(-)).
Though the nitrite anion is way more nucleophilic than the nitrate anion it still requires better leaving groups like the bromide or iodide. Ethyl
chloride might give a small yield of nitroethane even with NaNO2 if an optimal solvent is used, but it might also give a lot more of the side product,
ethyl nitrite, which tends to condense with nitroethane thus destroying it. I would dare to say that the only reasonable way of preparing nitroethane
from ethyl chloride is by using silver nitrite, but on the other side any reasonable person would rather use ethyl bromide or ethyl iodide anyway. Not
only because they are several thousand times more reactive, but also because they are much more easy to prepare (or buy given that they are liquids).
| Quote: | last time I tried to prepare ethyl chloride by adding a 25%HCl solution to a mix of ethyl alcohol and konz. H2SO4.
I heated it a little bit and it envolved white gases, I tried to condense them but it does not work, not even with a ice-alcohol mix.
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The white fume was moist hydrogen chloride gas. Hydrogen chloride only condenses bellow -85°C at normal pressure.
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Read the The ScienceMadness Guidelines!
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Per
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| Quote: | | The white fume was moist hydrogen chloride gas. Hydrogen chloride only condenses bellow -85°C at normal
pressure. |
I feared that, so it is proved that the method with H2SO4 does not work at all.
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Random
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Is it possible to use 36% ethanol and zinc chloride solution in HCl(aq) to make ethyl chloride or I need to have anhydrous reagents?
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Per
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wouldn't give a reasonable result, but ethanol is OTC as spirit with 94% ethanol. also is't recommended to use anhydrous ZnCl2 and dry HCl.
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bbartlog
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I've only done this with IPA (to make 2-chloropropanol), but I think 36% alcohol plus aqueous HCl will give you way too much water for the reaction to
proceed. Ideally (to maximize yield) you would want dry HCl gas bubbled into dry ethanol with anhydrous ZnCl2. But unlike some reactions (say,
Grignard reagent preparation) you can have some water and still get results. Still at a minimum I would suggest 95% ethanol and anhydrous ZnCl2; you
would then have a chance with aqueous HCl. Alternatively, 95% ethanol plus ZnCl2 hydrate plus HCl gas would probably also be dry enough
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~Anthrax~
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Unless I'm missing something obvious, surely ethylchloride (chloroethane) can be made from ethanol and phosphorus pentachloride?
CH3CH2OH + PCl5 -----> CH3CH2Cl + POCl3 +HCl
~Anthrax~
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Random
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Thanks for the responses, maybe I will try it on test tube scale with those reagents though to obtain even small yield, just to get some experience
with that stuff. After that I will try anhydrous ZnCl2, 96% ethanol and 19% HCl(aq).
@Anthrax
http://www.ucc.ie/academic/chem/dolchem/html/comp/ethanol.ht...
| Quote: | Halogenation or Substitution of Ethanol with PCl5
Ethanol reacts with phosphorus pentachloride at room temperature to form hydrogen chloride, ethyl chloride (i.e. chloroethane) and phosphoryl
chloride.
C2H5OH + PCl5 ==> C2H5Cl + POCl3 + HCl
Ethanol Phosphorus Ethyl Phosphorus Hydrogen
Pentachloride Chloride Pentachloride Chloride
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It should be possible.
[Edited on 16-2-2011 by Random]
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Sedit
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Random a test tube scale will more then likely provide little information and be dishearting. I tryed the same with EtBr and got nothing from a test
tube scale while I got greater then 75% IIRC performing the synthesis at a one mol scale. I feel its a synthesis of inherited losses and a test tube
does not produce enough to cover those losses.
Knowledge is useless to useless people...
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fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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Random
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Thanks for that information, it would be actually dissapointing to see that test tube scale produces nothing and then loose will to try bigger scale
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Nitro-esteban
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I mixed 12.5 grams of 80% ethanol with 27.3 grams of 29% HCl and then added a few ml of a concentrated ZnCl2 solution and nothing happened!
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Fantasma4500
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well ofcourse, nitro-esteban..
this reaction relies on anhydrous(-ness?)
so not having it all anhydrous does obviously not work
one approach by what i read here would be H2SO4 98% + NaCl > anh. HCl (g)
anh. HCl(g) + Zn (s) + EtOH (aq) > anh. ZnCl2 (which then reacts with the EtOH to form EtCl)
i dont see anything pointing away from also using Cl2 gas
in which i have discovered can be generated relatively slowly but in high concentration by Na2Cr2O7 + HCl (probably many other dichromates would work,
this is because i store dichromate stored in liquid with HCl in a glass bottle)
i must say, tho 'Per' probably isnt around the forum anymore, zinc is very easy to get a hold of
its used for fishing weights, anti corrosion blocks for boats, gutters, car wheel balance pieces, heavy duty battery casings,
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foxofax474
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Quote: Originally posted by Fantasma4500  |
one approach by what i read here would be H2SO4 98% + NaCl > anh. HCl (g)
anh. HCl(g) + Zn (s) + EtOH (aq) > anh. ZnCl2 (which then reacts with the EtOH to form EtCl) |
Does this method produce EtCl in dissolved in the EtOH or does it bubble out as a gas?
(∩^o^)⊃━☆ the proof is by magic
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clearly_not_atara
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According to Raoult's law, the product is most likely a gas, since the rxn is sluggish at low temperatures.
My suggestion: don't make ethyl chloride. Alkylating agents are a very bad starting point for someone new to chemistry.
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sykronizer
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Zinc metal is easily obtainable from "C" or "D" sized carbon/zinc batteries. The whole outer metal case (contacting the electrolyte) is the Zinc
electrode. Also, it's Silver NITRITE not nitrate...But Atara is right, judging by your lack of knowledge (no offense) do not attempt this, you are
only going to be disappointed or worse. Be wise, find another source other than attempting a synthesis that you aren't 100 percent confident with.
There is almost always an alternative route to any problem.
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jackchem2001
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From https://www.orgsyn.org/demo.aspx?prep=CV2P0279, this may work with NaCl and ethanol instead
| Quote: | | If methyl bromide is not available, it may be generated as follows: 500 g. of 95 per cent sulfuric acid is added slowly, with shaking, to 400 g. of
ordinary methyl alcohol, cooled by an ice bath. Six hundred grams of sodium bromide is suspended in one half of this mixture in a 1-l. round-bottomed
flask, fitted with a two-holed stopper holding a dropping funnel and a delivery tube. The evolution of methyl bromide is started by heating the flask
with a water bath at 50°, and the remainder of the methyl alcohol-acid mixture is added slowly from the funnel as the volume of the mixture in the
flask decreases. As the rate of evolution of the gas falls off the temperature is slowly raised until no more methyl bromide is generated and the
contents of the flask have become completely solid. The flask is shaken from time to time during the generation to mix the components more thoroughly.
The evolved gas is dried by passage through a tower of potassium hydroxide pellets. |
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